The 401(k) plan is required to send you a Form 1099-R for this distribution from the 401(k) and it must be reported. The gross amount shown in box 1 of the Form 1099-R will appear on Form 1040 line 16a or Form 1040A line 12a. Provided that the entire taxable amount shown in box 2a of the Form 1099-R was rolled over, the entire distribution will be excluded from line 16b or 12b making the distribution nontaxable.
